Shield for sanding drum slots



Dec. 24, 1946. T, BONKQWSK] 2,413,165

`SHIELD FOR SANDING DRUM SLOTS Filed April 24, 1945 INVENTOR: TEOF IL L. BONKOWSKI *1ro .3 .awww/Pfff@ AGENT Patented Dec. 24,1946

UNITED STATES PATENT OFFICE 2,413,165 l SHIELD FUR SANDING DRUM SLOTS Teoil L. Bonkowski, Los Angeles, Calif.

Application April 24, 1945, Serial No. 590,025

2 Claims.

This invention relates to rotating shaftmounted drums or wheels for the sanding of wooden, plastic, metal and other articles whose surfaces have narrowly recessed sections more or less inaccessible to ordinary sanding means, the drum containing a plurality of flexible sanding or abrasive strips of cloth, paper or otherwise, the free or working ends of the strips protruding outside of the peripheral wall of the drum or wheel and respectively thru a corresponding plurality of slots, each of said free ends being generally stili"- ened or backed by a thereto respective, adjacent one of a corresponding plurality of stiffening means, generally small brushes.

Sanding strips are coated only on one side with thereto bonded grains of abrasive material. The coated side therefore of the working end exercises an abrading effect on the coated-side-confronting edge of the respective slot. Since a longer life of the drum or wheel is a desideratum and since the body of the drum or wheel is preferably of a soft metal or plastic to permit ease and economy of fabricating it, this invention concerns itself particularly with special protecting means for eliminating the otherwise more or less serious abrading of said coated-side-confronting edge and the thereupon consequent premature consumption of the drum. No means for this purpose have ever been employed before on sanding drums. The combination therefore of a drum with such means constitutes the basic object and advantage of this invention, in which a certain replaceable shield constitutes one of the elements thereof.

A subsidiary object and advantage is quick and facile replaceability of said shield.

A further object and advantage is a guarantee against the accidental dislodgement of said shield while the drum is in use.

Although there are many arrangements of edge-protecting means based on the principles of this invention that will be conceived by persons skilled in the art, I prefer to select a simple and typical one of them as illustrative of said principles and constituting therefore the subject of this specication and of the herewith accompanying drawing, in which- Figure 1 is a plan view of a drum embodying said selected arrangement of edge-protecting means.

Figure 2 is an elevation view of the same as seen from the side thereof that is opposed to the shaftmounted side.

Figure 3 is an enlarged view of one of the respective said shields in said edge-protecting means.

Figure 4 is an enlarged sectional View of said shield and certain shield-retaining means, as seen in the plane 4 4 in Figure 1.

Referring to Figures 1 and 2, the respective sanding drum is indicated by I ll. The main body thereof is constituted of a base plate II, secured to a rotating shaft, not shown, by a hub I2, and integral with a peripheral Wall I3, which may be of circular cross-sectional form or of any other symmetrical form. The axis of symmetry of the drum, which is also the aXis of rotation thereof, is indicated by S-S. A detachable cover for the drum is indicated by I4,

successively spaced around the drum in peripheral wall I3, is a plurality of strip-slots or openings or, simply, slots, I5, I6, Il, I8, I9, 2U, 2| and 22. Corresponding to them respectively are the shields, 23, 24 25, 26, 21, 28, 29 and 30, which are conceivably of spring steel and which are adapted to embrace and be retained by the coated-sideconfronting edges respectively of said slots in the order given. The free or working ends of the thereto respective said sanding strips are indicated by 3I, 32, 33, 34, 35, 36, 31'and 38.

In. Figure 3, the disposition of the abrasiveor coated-side-confronting edge of the respective said strip slot is indicated by the plane G-G.

Referring to Figure 4, one of saidshields, 23, is shown embracing and being retained by the respective said co-ated-side-confronting edge I5A of slot I5, which edge is provided with a therein molded or cast bead I5B, which permits one, when the cover I4 is removed for the purpose, to slip the shield 23 axially parallelwise onto said edge IEA and, yet, because of the locking disposition of bead IEB within the arced section 23A of the shield, bead I5B restrains any appreciable movement of shield 23 toward the opposed, other edge of slot I5, with the thereupon ensuing obstruction of the slot. AXially parallel displacement of shield 23 is prevented by cover I 4. The described relationship between the bead or shield-retaining means, I5B, and the arced section 23A constitutes said previously mentioned guarantee against the accident-al dislodgment of said shield.`

Said slot I 5 and the shield are therefore respectively provided wlth the two mutually coacting parts, namely, bead IEB and arced section 23A, which are adapted to permit the drum-axially parallel removal and installation of the shield from and in said drum and to restrain displacement of the shield toward the other ofthe two edges of the slot. The above applies of course to each combination of slot and shield among said slots and shields. In Figure 4, the arced section 23A is schematically represented as being larger than the bead by a greater amount than is actually the case in practice. The space defined by the arced section, in which the bead is received, is in practice somewhat smaller.

I claim:

1. In a sanding drum, the combination of a drum having a peripheral Wall formed with a plurality of spaced slots, one long edge of said slots being formed with a bead therealong and a shield removably tted over each said long edge and bead, and said shield having an enlarged portion to receive the beaded edge of the drum, and parallel leg sections embracing the peripheral Wall beyond the bead.

2. In a sanding drum, the combination of a drum having a peripheral wall formed with a plurality of slots spaced therearound through which abrasive strips are extended, a peripheral wall along one long edge of each slot being beaded, and removable wear clips passed over the peripheral Wall and over beaded edges thereof and being held to the peripheral Wall behind said beads.

TEOFIL L. BONKOWSKI. 

